<p>This study investigates the lateral behavior of partially rock-socketed piles through a comprehensive experimental program utilizing instrumented model piles. The model piles were embedded in a two-layer soil profile comprising a surface layer of loose sand underlain by a simulated homogeneous weathered rock stratum, represented by concrete in a laboratory setting. Piles were socketed into the rock layer up to a maximum depth of 3D (three times the pile diameter), with socketing depths incrementally varied at intervals of 0.5D. Tests were conducted across various length-to-diameter (L/D) ratios by altering pile diameters to assess the influence of geometrical configurations on lateral response. The performance of socketed piles was compared against that of non-socketed counterparts. The experimental results highlight the significant influence of both socketing depth and pile embedment in soil on lateral resistance, bending behavior, and the effective depth of fixity. Notably, for piles with larger free-standing heights, the location of the maximum bending moment shifted toward the soil–rock interface. Additionally, increased socketing depth resulted in enhanced moment resistance at the interface, accompanied by a marked reduction in lateral deflections. These findings provide valuable design guidance by highlighting the shifting importance of bending moment constraints over deflection limits and the influence of pile stiffness on the depth of fixity.</p>